According to The Telegraph, many of those who had used the paints in question had removed the furniture from the effected room or rooms, bleached the carpets and washed bedding, all in a bid to determine where the smell was coming from. It was only then that some realized the smell was coming from the paint.

Complaints themselves have ranged from one individual stating that his room smelled like “a dead soggy mouse,” while someone else claimed their bedroom was “practically uninhabitable.” Yet another customer stated that they had hired a plumber, an electrician and a gas man to try to determine what was causing the smell, but in the end found out it was the paint. There is also a question of the lengths B&Q will go to compensate customers, as some used the effected coatings while completely redecorating certain rooms.

B&Q, a British home improvement and DIY chain, and the sole vendor of Valspar paints in the U.K., has offered to compensate customers who had used the effected products

Valspar has recommended painting the “offending walls” with two coats of an alkaline sealer, then put a coat of the paint of their choice overtop. However, some still worry about what caused the problem to being with and whether more coats of paint is enough of a fix.

“What concerns me is that it seems the problem is caused by bacteria growing in the paint,” Charlotte Quine, of Brighton, England, told BBC Radio 4’s You and Yours. “Until Valspar is prepared to investigate and say definitively what is causing this problem, I’m slightly concerned about just painting over it. It’s kind of like sweeping it under the carpet.

“If there is a bacteria growing in my walls, I want to know what it is and whether it’s going to cause any problems.”

Coating Conundrum

It turns out that the bacteria is not growing in the paint, per say, but in the paint can, and is unlikely to be dangerous, according to Graham Hill, managing director of ECHA Microbiology in Cardiff.

“It's a well-known issue in the paint industry," Hill said. “The bacteria grow in the can and release hydrogen sulfide gas which is the bad egg smell, and ammonia which is the urine smell.”

Valspar confirmed with Durability + Design News that the reaction occurred because the company had removed a specific additive from the paint. The company did not disclose what the additive was.

Hill noted that due to new restrictions on preservatives paint manufacturers can use under E.U. law, the problem is becoming more common.

"There's tighter and tighter restrictions on what preservatives we can use," Hill went on to say. "We've taken solvents out of paints and this does make them more susceptible to bacterial growth. Alkali [sealant] should break down hydrogen sulfide, so it shouldn't smell as much."

In a recent statement, Valspar specified that the additive had been put back into eight of its 140 paint products. According to the company, the ammonia-type odor occurs rarely, and most often it is on walls that are particularly porous, where the wall is exposed to heat and/or direct sunlight. The odor should gradually wear off over time.

B&Q has encouraged customers effected by the coating conundrum to reach out to their customer service helpline.